Multi-purpose convertible furniture

ABSTRACT

A convertible furniture article (1) can be configured alternatively to provide a bench-type seat, a picnic table or work bench, or a platform or staging. The article has a rigid base frame (2) which supports a seat (4) and a movable top structure that can serve as a table top (3), a platform, or a back rest associated with the seat. Two such articles can be juxtaposed in confronting relation to provide a picnic table. The article can be designed to provide seating for one or more individuals according to its size, and can also serve as a work bench or a desk with an adjustably inclinable top surface.

BACKGROUND OF THE INVENTION

a) Field of the Invention

This invention relates to a new or improved multi-purpose convertiblefurniture article and in particular to an article that can provide,amongst other uses, a bench-type seat, or a combined table and seat, inthe latter configuration the article also being usable as an elevatedplatform or staging.

b) Description of the Prior Art

Convertible picnic-type tables have previously been proposed in variousforms, to provide articles that can be used as tables or benches,sawhorses, scaffolding or other supports, and examples of such articlescan be seen in U.S. Design Pat. No. D-265,787 and also in U.S. Pat. No.1,792,737 Greenstreet, U.S. Pat. No. 4,606,575 Kodet and U.S. Pat. No.4,615,559 Blondeau. U.S. Pat. No. 4,801,175 Albanese shows an example ofa furniture article that provides a convertible bench/table. However theAlbanese structure is not useful as a support platform since it does notprovide a sufficiently stable support for the table top when in thehorizontal position. U.S. Pat. No. 4,913,488 Donnell JR. shows anotherexample of convertible furniture which has a support member rotatablymounted on the frame and movable from a seat back position to a tabletop position. However in the table top position Donnell's support memberis clearly unsuitable for use as a support platform since is onlysupported over a relatively narrow portion in the front to backdirection nor would it provide the desired degree of stability for useas a support platform. It is believed that few of the prior art designshave been commercially successful, one possible reason being that theyare inadequately designed or unduly complicated so as not to beeconomically viable. Such prior art designs of convertible bench/tablesfurthermore lacked stability in the table configuration.

SUMMARY OF THE INVENTION

The aim of the present invention is to provide a multi-purposeconvertible furniture article that is of sturdy and relatively simpleconstruction and that will, in particular, be stable when used in atable or platform configuration.

Accordingly the invention provides an article of furniture comprising: asubstantially rigid base frame having four feet regularly arranged inlongitudinally aligned front and rear pairs which pairs are spacedtransversely from each other to provide a stable support for saidarticle upon a horizontal surface; said frame including longitudinallyspaced sub-frames extending transversely and from top-to-bottom of saidframe, said sub-frames being rigidly interconnected by vertically andtransversely spaced horizontally extending frame elements and by bracemeans; two of said frame elements comprising a pair of longitudinallyspaced horizontal supports each rigidly attached at transversely spacedlocations on said frame and having end portions projecting transverselybeyond a rear side of said frame; a horizontal seat carried on andextending between said end portions; said article further including atable top that is selectively movable between a horizontal positionwherein it is supported on a top section of said frame, and a lowerposition wherein it is supported on said frame in a position extendingupwardly from one longitudinal edge of said seat so as to provide abackrest, guide means interacting between said table top and said frameto accommodate such movement of the table top; retainer meansselectively operable to secure said table top in said horizontalposition wherein it is transversely offset relative to said seat.

The furniture article can be made of any suitable material, butconveniently can be fabricated substantially entirely from wood. Withoutrequiring the furniture article to be excessively weighty, it can beconfigured to provide the required stability when used as a platform orstaging by arranging the front feet to be positioned more or lessdirectly below the front edge of the table top. Similarly the rear feetare positioned directly below or not far forwardly of the rear edge ofthe seat so that the furniture article will not lose its stability evenwhen the user's weight is concentrated on the rear edge of the seat.

For convenience in moving the article, one or other of the pair of feet(preferably the rear pair) may include wheels so that the furniturearticle can be lifted at the side opposite where the wheels are locatedand readily transported by being rolled on the wheels.

The guide means for the table top is preferably provided by an elongateslot formed in a stringer that extends across the width of the undersideof the table top in the front to rear direction, each of these slotscooperating with a respective pin in the adjacent end of the base framein the upper rear area thereof. In the horizontal position of the tabletop the pin is received in one end of the slot so that the table top canbe moved transversely and pivoted into the bench backrest position.

Preferably at each end of the table there is a retaining pin that, whenthe table top is in its horizontal position can be inserted through theforwardmost end of the slot and engaged in a socket in the adjacentupper front portion of the base frame to secure the table top againstrearward or pivotal movement. It may be desirable to arrange for theentire weight of the table top and any load supported thereon to betransmitted to the base frame through the pivot pins and the retainingpins.

It is also desirable to include adjustable support means through whichthe table top can be supported at various inclined positions. Suchsupport means could be in the form of a pivoted link at each end of thetable top having a series of holes therein enabling the retaining pin tobe passed through a selected hole to engage in the base frame socket, sothat the pivoted link then supports the table top at the desired angleof inclination.

As referred to above, the convertible furniture article can beconfigured so that it forms a bench or a table, and can also be utilizedas a support platform, a sawhorse, a combination work bench, a desk, andindeed for many other purposes as will occur to the user. If desired, itcan be designed to be collapsible so that it can be disassembled forshipping or storage.

BRIEF DESCRIPTION OF THE DRAWINGS

Numerous features and details of the invention will be more fullyunderstand from the following description of specific embodiments, givenby way of example only, when read in conjunction with the accompanyingdrawings wherein:

FIG. 1 is a perspective view, from the rear and one end, of a preferredembodiment of the convertible furniture article;

FIG. 2 is a perspective view corresponding to FIG. 1 showing thefurniture article in a modified configuration as seen in FIG. 6;

FIG. 3 is a plan view;

FIG. 4 is a front elevational view of a second embodiment, that ismodified by the inclusion of wheels at the lower end of the front legs;

FIG. 5 is an end elevational view of the article as seen from the righthand side of FIG. 4;

FIG. 6 is a view corresponding to FIG. 5 but showing the furniturearticle in an altered configuration;

FIG. 7 is a view corresponding to FIG. 5 showing the article in yetanother configuration;

FIG. 8 is an end elevation showing two such convertible furniturearticles juxtaposed to provide a picnic table;

FIG. 9 is an enlarged fragmentary front elevational view showing aportion of the article as seen in FIG. 4; and

FIG. 10 is a view corresponding to FIG. 9 showing a modification.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The furniture article 1 comprises a sturdy and rigid base frame 2 onwhich is supported a table top 3, and a longitudinally extending seat 4that projects rearwardly from the frame.

The frame may be fabricated of any desired material and as shown in thedrawings comprises two vertically oriented longitudinally spacedsub-frames 5 which are rigidly interconnected to form the base frame.Each sub-frame 5 is of generally A-shape as seen in side view comprisinga generally upright front leg 6 and an upwardly and forwardly inclinedrear leg 7, these legs being interconnected by a transverse horizontaltop member 8 near their upper ends and at about mid-height by atransverse horizontally extending intermediate member 9, the members 8and 9 extending in what for convenience is herein described as the frontto rear direction of the article. The members 8 and 9 are rigidlyinterconnected to the legs 6 and 7 by suitable fastening means, asillustrated by bolts 10.

Each intermediate horizontal member 9 projects rearwardly of the leg 7and carries one end of a seat 4 formed as shown by two timber planks 15attached as by nailing to the extensions 11, the outermost plank 15having centrally therein a hand grip aperture 16.

As best seen in FIG. 4, the end sub-frames 5 are rigidly interconnectedby a longitudinally extending member 17 spaced below the upper ends ofthe sub-frames, this being secured to the front legs 6 and reinforced byangularly arranged braces 18. The top ends of the sub-frames 5 arefurther interconnected by longitudinally extending wooden planks 19screwed to the tops of the legs 6 and 7. In the embodiment of FIGS. 1and 2 the lower ends of the legs provide widely spaced feet 6a, 7awhereas in the embodiment of FIGS. 4 to 8 the feet at the lower ends ofthe front legs 6 are coaxial pairs of wheels 20.

The table top 3 comprises a number of longitudinally extending woodenplanks 22 extending in closely spaced relationship and interconnected ontheir undersides at each end on the outboard side of the adjacentsub-frame 5 by a transverse stringer 23 extending as seen in FIG. 1 inthe front to rear direction, the stringers being wooden members to whichthe planks 22 are nailed to provide therewith a rigid table topstructure which has a transverse width in the front to rear direction(see FIG. 4) that only slightly exceeds the width of the top end of thebase frame 2. Each stringer 23 has a longitudinal through slot 24therein, this slot having a length that is only slightly less than thelength of the stringer. A pivot pin 25 mounted in the upper rear cornerof each sub-frame 5 projects laterally therefrom and extends through theslot 24 in the adjacent stringer, the pins 25 being coaxial and togetherforming a pivot axis for the table top.

Horizontally offset from the pivot pin 25, each sub-frame 5 has a socket26 (FIG. 6) which is aligned with the front end of the respective slot24 and which receives a retaining pin 27 which can be passed from theoutboard side through the front end of the slot. It will be seen thatwith the retaining pin positioned in its socket as illustrated in FIG.4, the table top is essentially immobilized. In this position, as shownin FIG. 9, the planks 22 of the table top are spaced slightly above thehorizontal planks 19 on top of the sub-frame, and accordingly the weightof the table top and of any load supported thereon is transmitted to thebase frame through the pivot pins 25 and retaining pins 27. Thus thepins 25 and 27 provide a solid abutment supporting the table top in itshorizontal position and do not rely on any frictional force in thissupporting action. Additionally, the planks of the table top have only asmall clearance above the planks 19 at the top of the base frame (seeparticularly FIGS. 9 and 10) and so can provide additional support tothe table top in the event that it deflects downwardly in the middleunder load. Additionally, the rigid base frame 2 provides a safetyfeature in that in the event of failure of one or more of the pins 25and 27, the table top will drop only a very short distance before itonce more finds solid support on the planks 19 at the upper end of thebase frame. In practice, the clearance between the planks 19 and theunderside of the table top boards 22 need be no more than two or threemillimeters. The possibility of failure of any of the pins 25, 27 isquite remote since these can easily be selected to be of a size andstrength sufficient to support any practical load with a high safetyfactor. Furthermore these pins provide an abutment type support for thestringers 23, and are loaded in shear to which they are highlyresistant. In no sense is there any reliance on gripping or frictionalforces to support the table top 3.

From the foregoing description it will be appreciated that when theretaining pins are withdrawn, the table top 3 can be moved transverselyto the rear (this movement being accommodated by the slots 24) and canthen be pivoted and moved downwardly to the position shown in FIGS. 2and 6 where the table top assumes an upwardly and rearwardly inclinedattitude and provides a backrest in relation to the seat 4. In thisbackrest position the table top 3 is supported against the upper rearedge 28 of the rear legs 7, this edge 28 being angulated as seen in FIG.5 to be somewhat more upright than the direction of orientation of theleg 7.

When it is required for the table top to be held at a slightinclination, the retaining pins 27 are withdrawn, the table top 3pivoted slightly upwardly at its front end around the pins 25, and afterreinsertion of the retaining pins 27, the table top is released so thatthe lower surfaces of the stringers 23 come to rest on the retainingpins 27. Minor variations in the inclination can be effected byproviding on the retaining pins 27 an eccentric polygonal camconfiguration (not shown) having a number of facets at differentspacings from the axis of the pin, in use these facets being selectivelyoriented to support the lower surfaces of the stringers 23.

Additional or alternative means can be provided for adjusting theinclination of the table top 3, as shown in FIG. 5 this being in theform of an elongate link or strut 29 lying against the underside of theplanks 23 on the outboard side of each stringer 23 and pivoted to thelatter by a pin 30. Each of the links 29 has a series of longitudinallyspaced holes 32 of a size to accommodate passage of the retaining pin27. Therefore when the retaining pin is withdrawn and the table toppivoted upwardly at its front about the axis of the pins 25, each link29 can be swung downwardly, and a selected one of its holes brought intoregister with the socket 26 whereupon the retaining pin can be insertedthrough that hole into the socket, and the link 29 will form a strut tosupport the table top at the desired inclination as illustrated in FIG.7. When not in use the links 29 are stowed against the underside of thetable top planks 22 and retained thereby suitable means, e.g. springs(not shown).

FIG. 9 shows the interconnection of the pivot pin 25 to the base frame5. The pivot pin is received in a bore 34 in the base frame and issecured by a washer 35 and a wing nut 36, there being a further washer37 between the head of the pivot pin and the outer side of the stringer23, the pivot pin passing with clearance through the slot 24.

Similarly, as seen in FIG. 10, the retaining pin 27 passes withclearance through the slot 24 to be received in the socket 26 formed bya bore in the front leg 6.

From the foregoing it will be appreciated that the described furniturearticle is readily convertible from the table configuration as shown inFIG. 1 to the seating configuration as shown in FIG. 2. What isparticularly advantageous about the convertible furniture article of thepresent invention is its stability when used as a platform or staging inthe configuration seen in FIGS. 1 and in 3 to 5. In this configurationthe upper surface of the table top 30 will be at a height of some 70 to75 centimeters above the ground support surface, and may readily beaccessed by a user employing the seat 4 as a step. With reference toFIG. 5 it will be seen that the retaining pins 27 and pivot pins 25between them provide a secure attachment and support for the table topupon the base frame 2, this support extending over the major part of thewidth of the table top as measured in the front to back direction.

Furthermore, the furniture article provides a secure and stable supportfor a user standing on the table top. Thus even if the weight of theuser is concentrated on the forwardmost edge of the table top asindicated by the arrow 40 in FIG. 5, the article will remain stable solong as the distance of the arrow 40 forwardly of the vertical plane 41of the forwardmost point of contact between the support frame 2 and theground, i.e. the location where the wheels 20 contact the ground, timesthe weight of the user, is less than the spacing between the plane 41and the center of gravity 42 times the weight of the furniturearticle 1. In other words the furniture article will remain stable solong as the following relationship holds true:

    L×D.sub.1 >W×D.sub.2

where:

L is the load produced by the weight of the user,

W is the weight of the furniture article,

D₁ is the spacing between the arrow 40 and the plane 41, and

D₂ is the spacing between the center of gravity 42 and the plane 41.

In comparing FIGS. 1 and 5 it will be seen that in the former, thecritical plane will coincide with the front of the feet 6a formed by thelower ends of the front legs 6 whereas in FIG. 5, with the wheelscentrally mounted on the front legs 6, the plane 41 is at anintermediate location about midway between the front and rear of thefeet 6a of front legs 6. Thus in order to increase the stability of thefurniture article it is preferable to ensure that the wheels 20 contactthe ground surface more or less directly below the front edge of thetable top 3. For this purpose, rather than the wheels being mountedcentrally in the front legs 6, they may be mounted with their axis inthe regions of the forward edge of the front legs (not shown).Alternatively, the front legs 6 may be angled forwardly downwardly toachieve the same effect. In the embodiment shown in FIG. 5 the ratio D₁: D₂ is in excess of 5 so that the furniture article can stably supporta load at the location of the arrow 40 of at least 5 times the weight ofthe furniture article.

Similarly, as shown in FIG. 5, the spacing D₃ of the center of gravity42 forwardly of the vertical plane defined by the rear end of the feet7a is at least 5 times greater than the spacing D₄ from this plane ofthe rear most part of the seat 4a, so that this location of the seat cansupport a load in excess of 5 times the weight of the bench withouttipping. If desired, the seat could be shortened or the rear feet 7aextended so that there is no overhang of the seat.

Because of the solid structure of the frame 2 and the wide based supportits provide for both the seat 4 and the table top 3, the furniturearticle when in the configuration shown in FIGS. 1 or 5 is extremelystable and provides a secure working platform for the user.

To ensure adequate stability for the article when used as a platform,the base frame (2) must support the table top (3) or at least half ofits transverse (i.e. front to back) width. Thus, with reference to FIG.5, the horizontal spacing between the pivot pins (25) and the retainingpins (27) must be at least 50%, preferably 75%, and most preferably from80% to 90% of the width of the table top (3). This combined with thewide base provided between the front and rear legs (6, 7) ensures a verystable support for the furniture article.

An alternative means (not shown) for adjusting the inclination of thetable top (3) as discussed in relation to FIG. 7 may be provided bylocating elongate support struts similar to the struts (29) on theinboard side of each stringer (23). This strut could be of metal orstrong plastic of a thickness about three millimeters, a width of about2.5 centimeters and a length of about 30 centimeters and pivoted on abolt the threaded end of which extends to the outboard side of thestringer (23) to be engaged by a wing nut by means of which the link canbe pressed against the inboard side of the stringer (23) to provide africtional force which will retain the link, when not in use, in aretracted position where it is hidden by the stringer (23), but fromwhich it can nonetheless readily be swung downwardly when it is requiredto support the table top at an inclination. This repositioning of thestrut from the outboard to the inboard side of the stringer (23) alsohas the advantage that it is now about 6 cm closer to the sub-frame (5)and can thus more strongly resist lateral movement of the table top (3).

Another means of preventing or substantially eliminating lateralmovement of the table top (2) when it is supported in an inclinedcondition is to provide a blocking means (not shown) which can beselectively engaged to prevent movement of the slot (24) relative to thepivot pin (25). The blocking means could be in the form of a detent (notshown) mounted on the stringer (23) and capable of being inserted intothe slot (24) near the rearward end thereof when it is desired to blockmovement of the pin (25) lengthwise of the slot (24).

We claim:
 1. An article of furniture comprising:a substantially rigidbase frame having four feet regularly arranged in longitudinally alignedfront and rear pairs which pairs are spaced transversely from each otherto provide a stable support for said article upon a horizontal surface,said front pair of feet being wheels; said frame includinglongitudinally spaced sub-frames extending transversely and fromtop-to-bottom of said frame, said sub-frames being rigidlyinterconnected by vertically and transversely spaced horizontallyextending frame elements and by brace means; two of said frame elementscomprising a pair of longitudinally spaced horizontal supports eachrigidly attached at transversely spaced locations on said frame andhaving end portions projecting transversely beyond a rear side of saidframe; a horizontal seat carried on and extending between said endportions; said article further including a table top having a length anda width, said table top being selectively movable between a horizontalposition wherein said table top is supported on a top section of saidframe, and a lower position wherein said table top is supported on saidframe in a position extending upwardly from one longitudinal edge ofsaid seat so as to provide a backrest, guide means interacting betweensaid table top and said frame to accommodate such movement of the tabletop; retainer means selectively operable to secure said table top insaid horizontal position wherein said table top is transversely offsetrelative to said seat; wherein said frame carries support means thatextend over a distance in the front-to-rear direction that correspondsto a major portion of the width of the table top such that in thehorizontal position the table top is stably supported on said supportmeans over a major part of the width of said table top; said article offurniture having a center of gravity and having a weight distributionsuch that when said article of furniture is supported on a horizontalsurface and the weight of a user is concentrated on the front of saidtable top, the article of furniture remains stable.
 2. An article offurniture as claimed in claim 2 wherein said seat has a rear edge thatprojects rearwardly beyond the rear pair of feet, said weightdistribution of the article being such that when said table top is inthe horizontal position the article will remain stable even when theentire weight of the user is concentrated on said rear edge of the seat.3. An article of furniture as claimed in claim 1 wherein said guidemeans comprises a pin and slot mechanism forming an interconnectionbetween said table top and said frame.
 4. An article of furniture asclaimed in claim 1 wherein said guide means comprises at each end ofsaid frame a longitudinally extending pivot pin received within acorresponding transversely extending slot on the underside of said tabletop, said pivot pins being substantially coaxial, and said table topbeing movable transversely relative to and pivotable about the axis ofsaid pivot pins, said retainer means comprising retaining pins that areinsertable through said slots when the table top is in horizontalposition, each said retaining pin being received within a socket in saidframe to inhibit horizontal or pivotal movement of the table toprelative to said frame.
 5. An article of furniture as claimed in claim 4wherein the weight of said table top and any load supported thereon istransmitted to said frame solely through said pivot pins and saidretaining pins.
 6. An article of furniture as claimed in claim 4 whereineach said slot is provided in an elongate transverse member attachedbeneath said table top, each said transverse member having a lowersurface that is spaced below said slot and that can be rested on therespective retaining pin to support said table top thereon at aninclination to the horizontal.
 7. An article of furniture as claimed inclaim 5 including means to effect support of said table top selectivelyin any of a plurality of inclined positions on top of said frame.
 8. Anarticle of furniture as claimed in claim 7 wherein said supporteffecting means comprises a pivoted link adjacent each end of said tabletop, each said pivoted link having a series of holes spaced therealong,said links being positionable so that selected holes therein are inregister with said sockets such that the retaining pins can be engagedwith said sockets through said selected holes and said links form strutsto support said table top at a desired angle of inclination.
 9. Anarticle of furniture as claimed in claim 1 wherein each said sub-framecomprises a generally upright front leg, an upwardly and forwardlyinclined rear leg, and transversely extending supports interconnectingsaid legs adjacent their upper ends and at an intermediate location intheir height.
 10. An article of furniture as claimed in claim 1 whereineach said sub-frame comprises a generally upright front leg, an upwardlyand forwardly inclined rear leg, and transversely extending supportsinterconnecting said legs adjacent their upper ends and at anintermediate location in their height and wherein said longitudinallyspaced horizontal supports provide said intermediate connection of thefront and rear legs of the respective sub-frame.
 11. An article offurniture as claimed in claim 1 wherein said seat has a handholdprovided therein to facilitate grasping and lifting the rear side of thearticle.
 12. An article of furniture as claimed in claim 1 wherein atleast said table top is of wood.
 13. An article of furniture as claimedin claim 1 which is fabricated substantially entirely of wood except forsaid wheels, said pivot pins, said retaining pins, and fasteninghardware.
 14. An article of furniture as claimed in claim 5 wherein saidbase frame has a top end that provides a secondary horizontal supportingplatform spaced closely below the underside of the table top andproviding a large auxiliary supporting surface that becomes operative inthe event of failure of any of said pivot pins and said retaining pins.15. An article of furniture as claimed in claim 7 wherein each saidpivoted link is positioned on the inboard side of a stringer member thatextends transversely on the underside of the table top.
 16. An articleof furniture as claimed in claim 1 wherein in said lower position thetable top has a longitudinal marginal portion thereof located at aposition that is below and in front of the top of said seat.
 17. Anarticle of furniture as claimed in claim 1 wherein in said lowerposition the table top has a longitudinal marginal portion thereoflocated at a position that is below and in front of the top of said seatand wherein in said lower position the table top rear edge rests uponsaid horizontal supports in front.
 18. An article of furniturecomprising:a substantially rigid base frame having four feet regularlyarranged in longitudinally aligned front and rear pairs which pairs arespaced transversely from each other to provide a stable support for saidarticle upon a horizontal surface; said frame including longitudinallyspaced sub-frames extending transversely and from top-to-bottom of saidframe, said sub-frames being rigidly interconnected by vertically andtransversely spaced horizontally extending frame elements and by bracemeans; two of said frame elements comprising a pair of longitudinallyspaced horizontal supports each rigidly attached at transversely spacedlocations on said frame and having end portions projecting transverselybeyond a rear side of said frame; a horizontal seat carried on andextending between said end portions; a table top having a length and awidth, said table top being selectively movable between a horizontalposition wherein said table top is supported on a top section of saidframe, and a lower position wherein said table top is supported on saidframe in a position extending upwardly from one longitudinal edge ofsaid seat so as to provide a backrest; guide means interacting betweensaid table top and said frame to accommodate such movement of the tabletop said guide means comprising at each end of said frame alongitudinally extending pivot pin received within a correspondingtransversely extending slot on the underside of said table top, saidpivot pins being substantially coaxial, and said table top being movabletransversely relative to and pivotable about the axis of said pivotpins; retainer means selectively operable to secure said table top insaid horizontal position wherein said table top is transversely offsetrelative to said seat, said retainer means comprising retaining pinsthat are insertable through said slots when the table top is in itshorizontal position, each said retaining pin being received within asocket in said frame to inhibit horizontal or pivotal movement of thetable top relative to said frame; wherein said frame carries supportmeans that extend over a distance in the front-to-rear direction thatcorresponds to a major portion of the width of the table top such thatin the horizontal position the table top is stably supported on saidsupport means over a major part of the width of said table top; saidarticle of furniture having a center of gravity and having a weightdistribution such that when said article of furniture is supported on ahorizontal surface and the weight of a user is concentrated on the frontof said table top, the article of furniture remains stable.
 19. Anarticle of furniture as claimed in claim 18 wherein the weight of saidtable top and any load supported thereon is transmitted to said framesolely through said pivot pins and said retaining pins.
 20. An articleof furniture as claimed in claim 19 wherein said base frame has a topend that provides a secondary horizontal supporting platform spacedclosely below the underside of the table top and providing a largeauxiliary supporting surface that becomes operative in the event offailure of any of said pivot pins and said retaining pins.
 21. Anarticle of furniture as claimed in claim 18 wherein said front pair offeet comprise wheels.
 22. An article of furniture as claimed in claim 21wherein said seat has a hand hold provided therein to facilitategrasping and lifting the rear side of the article such that it can berolled on said wheels.
 23. An article of furniture as claimed in claim18 which is fabricated substantially entirely of wood except for saidpivot pins, said retaining pins, and fastening hardware.
 24. An articleof furniture as claimed in claim 18 including means to effect support ofsaid table top selectively in any of a plurality of inclined positionson top of said frame.